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/*]]>*/</style><title>第4章 字符串操作与正则表达式</title></head><body>
<div><span style="font-family: 微软雅黑; font-size: 18pt; font-weight: bold; padding-left: 49pt; line-height: 190%">第</span><span style="font-family: Consolas; font-size: 18pt; font-weight: bold; padding-left: 49pt; line-height: 190%">4</span><span style="font-family: 微软雅黑; font-size: 18pt; font-weight: bold; padding-left: 49pt; line-height: 190%">章 &nbsp; &nbsp; &nbsp; &nbsp;字符串操作与正则表达式</span></div>
<div><span style="font-family: 微软雅黑; font-size: 16pt; padding-left: 70pt; line-height: 170%">4.1 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; padding-left: 70pt; line-height: 170%">示例：智能表单邮件</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">mail()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">bool </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">mail</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">(string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt; line-height: 190%">$to</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">, string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt; line-height: 190%">$subject</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">, string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt; line-height: 190%">$message</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">, [string &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt; line-height: 190%">$additional_headers</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%"> [, string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt; line-height: 190%">$additional_parameters</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">]]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">$message</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">: </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">消息体，每行以</span><span style="font-family: Times New Roman; font-size: 11pt; font-weight: bold; color: #ff0000; padding-left: 40pt; line-height: 160%">\</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #ff0000; padding-left: 40pt; line-height: 160%">r\n</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">分隔，每行最长不超过</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">70</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">个字符。</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #c45911; padding-left: 21pt; line-height: 160%">$message = &quot;Line 1\r\nLine 2\r\nLine 3&quot;;</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; padding-left: 21pt; line-height: 240%">$message = </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #ff0000; padding-left: 21pt; line-height: 240%">wordwrap</span><span style="font-family: Consolas; font-size: 11pt; color: #c45911; padding-left: 21pt; line-height: 240%">($message, 70, &quot;\r\n&quot;);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">在</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">windows</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">中</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">php</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">与</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">STMP</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">服务器交互时，行开头的句号会被移除，可以采用下面语句来解决。</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #c45911; padding-left: 21pt; line-height: 240%">$text = str_replace(&quot;\n.&quot;, &quot;\n..&quot;, $text);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;$</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">additional_headers</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">:</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">额外的有效的</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">文件头</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，见</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">RFC2822</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">文档</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">, </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">例如</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">&quot;From:&quot;, &quot;Reply-To:&quot;, &quot;Cc:&quot;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">域等，多个文件头用</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">换行符</span><span style="font-family: Times New Roman; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">\</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">n\r</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">分开</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #c45911; padding-left: 21pt; line-height: 160%">$additional_header = &quot;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ff0000; padding-left: 21pt; line-height: 160%">From:</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #c45911; padding-left: 21pt; line-height: 160%"> webserver@example.com\r\n&quot;</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; line-height: 240%"> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;.&quot;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #ff0000; line-height: 240%">Reply-to:</span><span style="font-family: Consolas; font-size: 11pt; color: #c45911; line-height: 240%"> </span><a href="mailto:bob@example.com" style="font-family: Consolas; font-size: 11pt; text-decoration: underline; color: #0563c1">bob@example.com</a><span style="font-family: Consolas; font-size: 11pt; color: #c45911; line-height: 240%">&quot;;</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">When sending mail, the mail </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 240%">must contain a From header</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">. This can be set with the additional_headers parameter, or a default can be set in </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 240%">php.ini</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 240%">.</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">使用</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">mail()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数，必须将</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">php</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">设置为指向</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">邮件发送程序</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">。</span></div>
<div><br /></div>
<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.2 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">字符串的格式化</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">4.2.1 </span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">字符串的整理：</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">chop(), ltrim(), trim(), rtrim()</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">trim()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">去除开始和结束位置的空格，并将结果字符串返回</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">空格包括：换行符</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">\</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">n, </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">回车符</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">\</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">r</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，水平和垂直制表符</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">\</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">t\x0B, </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">字符串结束符</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">\0</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">和空格。</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">第二个参数可提供要过滤的特殊字符</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 190%">ltrim()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">函数，从字符串的开始处（左边）除去空格。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 190%">rtrim()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">函数，从字符串的结束处（右边）除去空格。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">chop()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">函数，</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">alias of rtrim()</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.2.2 </span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">格式化字符串以便显示（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">p79</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 190%">nl2br</span><span style="font-family: Consolas; font-size: 12pt; line-height: 190%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">函数，</span><span style="font-family: Consolas; font-size: 12pt; line-height: 190%">html</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">格式化，将换行符转换为</span><span style="font-family: Consolas; font-size: 12pt; line-height: 190%">XHMTL</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">中的</span><span style="font-family: Consolas; font-size: 12pt; line-height: 190%">&lt;br /&gt;</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 190%">printf</span><span style="font-family: Consolas; font-size: 12pt; line-height: 190%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">函数，将格式化的字符串输出到浏览器中。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">sprintf</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数，返回一个格式化了的字符串。</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">转换说明（</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 190%">%s</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">）的格式</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">%[</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; font-style: italic; color: #ff0000; padding-left: 21pt; line-height: 190%">&apos;</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">padding_character][-][width][.precision]type</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">以</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">%</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">开始，打印</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">%</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，必须使用</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">%%</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">padding_char</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">可选，默认填充空格，若非空格或</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">0</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，其它填充字符前须加</span><span style="font-family: Consolas; font-size: 11pt; color: #ff0000; padding-left: 40pt; line-height: 160%">&apos;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">为前缀</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">type</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">,</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">类型码，如</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">s,u</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">等</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">(p80)</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">带序号的参数方式</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">，</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">% </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">后添加参数位置，并以 </span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">$ </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">符号结束：</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">&quot;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #ff00ff; padding-left: 40pt; line-height: 190%">%2</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; color: #ff00ff; padding-left: 40pt; line-height: 190%">\$</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">.2f&quot;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">（即用格式说明符后第二个参数来替换）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">vprintf</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">，</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%"> </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">vsprintf</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">：格式字符串和</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 240%">参数数组</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.2.3 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">改变字符串中字母的大小写（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">p81</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">strtoupper</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">：将字符串转换为大写</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">strtolower</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">：将字符串转换成小写</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">ucfirst</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">：如果字符串第一个字符是字母，就将该字符转换为大写</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">ucwords</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">：将字符串每个单词的第一个字母转换为大写</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.2.4 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">格式化字符串以便存储（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">p81</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">）</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">字符插入</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">DB</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">中时，可能会被解释成</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">控制符</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，包括</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">引号</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">（单引、双引），</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">反斜杠</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">（</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">\</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">），和</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 170%">NULL</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">字符</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">。</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">须利用 </span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">\ </span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">进行转义，</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">\\ </span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">转义为</span><span style="font-family: 宋体; font-size: 12pt; text-decoration: underline; color: #0000ff; line-height: 170%">\\\\</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">addslashes()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">函数，将字符串重新格式化，即特殊字符加转义。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">stripslashes()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数，移除反斜杠。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">magic_quotes_gpc</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">配置指令，默认启用，使</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">php</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">自动添加或去除反斜杠。</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">gpc</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">即</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">GET, POST</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">和</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">cookie</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">来自</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">gpc</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">方法或方式的变量被自动包括在引号内</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">get_magic_quotes_gpc</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">函数，检查系统上的这个指令是否已启用。</span></div>
<div><br /></div>
<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.3 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">用字符串函数连接和分割字符串</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">4.3.1 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">使用</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">explode(), implode()</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">和</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">join() </span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">（</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">p83</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 190%">explode()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 190%">函数，</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #2f5496; padding-left: 21pt">array</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt"> explode(string separator, string input [, int limit]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">根据指定分隔符将字符串分割成小块，返回到数组中</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">limit</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">参数，限制分成字符串小块的数量。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">implode()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">和</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">join()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">函数，与</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">explode()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">相反效果，两函数效果一致。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.3.2 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">使用</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">strtok()</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">函数</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%"> (p84)</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">strtok()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数，一次只从字符串中取出</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%"> </span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">一些</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">片段</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">（即</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">令牌</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">）</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #2f5496; padding-left: 21pt">strtok</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">(string input, string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #2f5496; padding-left: 21pt">separator</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">separator</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">可为字符或字符串</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">输入的字符串会根据分隔字符串中的</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 190%">每个字符</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">来进行分割。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 170%">strtok</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数的调用方式</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">得到第一个令牌，调用</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">strtok</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，并带</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">两个参数</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">得到后续令牌序列，只使用</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">separator</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">参数</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">,</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">strtok</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">会保持自己的</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">内部指针</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">在字符串中的位置。</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">若要重置指针，再次调用带两个参数的</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">strtok</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #000000; line-height: 160%">4.3.3 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">使用</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">substr()</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">函数</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%"> (p84)</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">substr()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">string substr(string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ff00ff; padding-left: 21pt; line-height: 190%">string</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">, int </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ff00ff; padding-left: 21pt; line-height: 190%">start</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">[, int </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ff00ff; padding-left: 21pt; line-height: 190%">length</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt; line-height: 190%">]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">访问一个字符串的给定起点和终点的子字符串</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">返回子字符串的副本</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">仅使用一个</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">正数起点</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">：返回起点到字符串结束的整个字符串</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">仅使用一个</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">负数起点</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">：得到字符串发问的一个子串，最后一个字符位置为</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">-1</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 240%">length</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">，指定返回字符的个数</span></div>
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<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.4 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">字符串的比较（</span><span style="font-family: Calibri; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">p85</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">4.4.1 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">字符串的排序：</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">strcmp(), strcasecmp()</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 160%">和</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 160%">strnatcmp()</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">strcmp()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">int </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #2f5496; padding-left: 21pt">strcmp</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">(string str1, string str2);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">相等返回</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">0</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">str1</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">按字典顺序在</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">str2</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">后面，返回正数，否则返回负数</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">区分大小写</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">strcasecmp()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数，不区分大小写，其它同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">strcmp().</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">strnatcmp()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数，按</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">&quot;</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">自然顺序</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">&quot;</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">比较字符串，（如</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">2</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">小于</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">12</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">）</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">.</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">strnatcasecmp()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">函数，不区分大小写，其它同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">strnatcasecmp().</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.4.2 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">使用</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">strlen()</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">测试字符串的长度</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">e.g., </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">strlen</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">(&quot;Hello&quot;);</span></div>
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<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.5 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">使用字符串函数匹配和替换子字符串</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; padding-left: 21pt; line-height: 170%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 12pt; padding-left: 21pt; line-height: 170%">explode</span><span style="font-family: Consolas; font-size: 12pt; padding-left: 21pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 170%">和</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; padding-left: 21pt; line-height: 170%">strtok</span><span style="font-family: Consolas; font-size: 12pt; padding-left: 21pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 170%">之后再通过</span><span style="font-family: Consolas; font-size: 12pt; padding-left: 21pt; line-height: 170%">&quot;</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; padding-left: 21pt; line-height: 170%">==</span><span style="font-family: Consolas; font-size: 12pt; padding-left: 21pt; line-height: 170%">&quot;</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 170%">或函数</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; padding-left: 21pt; line-height: 170%">strcmp</span><span style="font-family: Consolas; font-size: 12pt; padding-left: 21pt; line-height: 170%">()</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 170%">进行比较</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 21pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 240%">还可以调用</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; padding-left: 21pt; line-height: 240%">字符串函数</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 240%">或</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; padding-left: 21pt; line-height: 240%">正则表达式</span><span style="font-family: 宋体; font-size: 12pt; padding-left: 21pt; line-height: 240%">来完成相同的操作</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.5.1 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">在字符串中查找字符串：</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">strstr(), strchr(), strrchr()</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">和</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">stristr()</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">strstr()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">（等价于</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">strchr()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">）</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">string strstr(string haystack, string needle);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">在一个较长的字符串中查找匹配的字符串或字符。</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">找到目标关键字的一个精确匹配则</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 240%">返回目标关键字及其后的字符串</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">，否则返回</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">false</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">stristr()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，不区分字符大小写，其它同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">strstr().</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">strrchr()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">，返回关键字及其最后一次出现到字符串末尾的字符串，其它同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">strstr().</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.5.2 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">查找子字符串的位置：</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">strpos(), strrpos()(p87)</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">strpos()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">函数</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">int strpos(string haystack, string needle [, int offset]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">建议使用</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">strpos()</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">来替换</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">strstr()</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，因为其</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">速度更快</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">返回的整数代表搜索字符串中</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">第一次出现</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">目标关键字的</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">位置</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，第一个位置为</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 160%">0</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">offset</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，指定被搜索字符串的开始搜索位置</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">关键字不在字符串中返回</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">false</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，应使用</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%"> </span><span style="font-family: Consolas; font-size: 11pt; color: #ff0000; padding-left: 40pt; line-height: 160%">=== false</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">来测试返回值。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">strrpos()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">函数，返回被搜索字符串中最后一次出现目标关键字子符串的位置，其它同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">strpos().</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.5.3 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">替换子字符串：</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">str_replace(), substr_replace()</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">str_replace()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，最常用字符串替换函数</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">mixed str_replace(mixed </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt">needle</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">, mixed </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt">new_needle</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">, mixed </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt">haystack</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt"> [, int </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt">&amp;</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt"> </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ed7d31; padding-left: 21pt">count</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">]));</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">用</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">new_needle</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">替换所有</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">haystack</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">中的</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">needle</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">返回替换后的结果</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">count</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">包含了要执行的替换操作的次数</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">可传递</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">数组</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，被替换单词、替换单词、返回均为数组</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">substr_replace()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，在</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">给定位置</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">中查找和替换字符串中选定的子字符串。</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">string substr_replace(string string, string replacement, int start int [length]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 190%">length</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">值为</span><span style="font-family: Times New Roman; font-size: 11pt; padding-left: 40pt; line-height: 190%">0</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">，则替换字符串实际上会插入到字符串中而不覆盖原有的字符串</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">正的</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 190%">length</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">表示用新的字符串替换掉的原字符串的长度</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 190%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">负的</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 190%">length</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">表示从字符串尾部开始到第</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 190%">length</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 190%">个字符停止替换</span></div>
<div><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; </span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">不给定</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">length</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">值表示从字符串</span><span style="font-family: Calibri; font-size: 11pt; padding-left: 40pt; line-height: 240%">start</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">位置开始一直到字符串结束。</span></div>
<div><br /></div>
<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.6 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">正则表达式的介绍</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">php</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">支持两种正则表达式语法：</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 170%">POSIX</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">和</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 170%">Perl</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">PCRE</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 170%">, Perl Compatible Regualr Expression</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">php5.3</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">版本中</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">Perl</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">风格不能被禁用，此处介绍</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 170%">POSIX</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">语法</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">POSIX</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">更简单，但是它们不是二进制安全的</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.1 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">基础知识</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">正则表达式</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">：一种描述一段文本模式的方法</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">精确匹配</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">用特殊字符指明表达式的</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">元意（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">meta-meaning</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">）</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 240%">:</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 240%">开始结尾模式、模式的部分重复、模式中的字符属于特定的某一类型、按特定字符的出现来匹配。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 160%">4.6.2 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 160%">字符集和类（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 160%">p89</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 160%">）</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">字符集：用于匹配属于特定类型的任何字符</span></div>
<div><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">.</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">字符</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 170%">：作为一个通配符来代替除换行符</span><span style="font-family: Consolas; font-size: 12pt; color: #000000; line-height: 170%">(\n)</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 170%">外的任何一个字符。</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">方括号（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">[]</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">）</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 170%">中的内容：是一个</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 170%">字符类</span><span style="font-family: 宋体; font-size: 12pt; color: #000000; line-height: 170%">，一个被匹配字符所属的字符集合。其中的表达式只匹配一个字符。</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">如：</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">[a-z]at, [aeiou]</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">描述一个范围</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">:[a-zA-Z]</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">指明字符不属于某个集</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">[</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #ff0000; padding-left: 40pt; line-height: 160%">^</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">a-z]</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">预定义的字符类：用于</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #ff0000; padding-left: 40pt; line-height: 240%">POSIX</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; color: #ff0000; padding-left: 40pt; line-height: 240%">风格</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">的正则表达式的字符类（</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">P90</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">）</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; color: #000000; line-height: 160%">4.6.3 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">重复</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">符号</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">&quot;</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">*</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">&quot;</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，表示这个模式可以被重复</span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; line-height: 170%">0</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">次或更多次</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，放在要作用的表达式的后面。</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">符号</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">&quot;</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">+</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">&quot;</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">，表示这个模式可以被重复</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; line-height: 240%">1</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 240%">次或更多次</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">，放在要作用的表达式的后面。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.4 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">子表达式</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">可将一个表达式分隔为几个</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">子表达式</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">， </span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">例如：表示</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">&quot;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">至少这些字符中的一个需要精确匹配</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">&quot;</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">使用</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">圆括号</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">来实现子表达式，如</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #c45911; padding-left: 21pt; line-height: 240%">(very)*large</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.5 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">子表达式计数（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">p91</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">）</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">花括号</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">{}</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">中的数字表达式来指定内容允许重复的次数</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">确切的重复次数，如</span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">{</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">3}</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">,</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">重复</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">3</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">次</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">重复的次数范围，如</span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">{</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">2,4}</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">,</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">重复</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">2~4</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">次</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">开底域的重复范围（</span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">{</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">2,}</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">表示至少重复两次）。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.6 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">定位到字符串的开始或末尾</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">可以确定一个特定的子表达式是否出现在开始、末尾或在两个位置都出现。</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">脱字符号（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">^</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">）</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">：用于正则表达式的开始，表示子字符串必须出现在被搜索字符串的开始处。</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">字符（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">$</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">）</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">：用于正则表达式的末尾，表示子字符串必须出现在字符串的末尾。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.7 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">分支</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">一条</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 240%">竖线</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">表示一个选择。</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.8 </span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">匹配特殊字符（</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">p92</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">）</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">特殊字符：</span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">.</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">, </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">$</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，</span><span style="font-family: Times New Roman; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">\</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">等，前面加上</span><span style="font-family: Times New Roman; font-size: 12pt; line-height: 170%">\</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">php</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">中必须将正则表达式模式</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #0000ff; line-height: 170%">包括在一个单引号字符串中</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">。</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 170%">双引号</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">引用的正则表达式带来复杂性：</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">双引号引用的</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">PHP</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">字符串中使用反斜杠字符，则必须使用两个反斜杠</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">表示一个包含了反斜杠字符的正则表达式的一个</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">PHP</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">字符串需要</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">4</span><span style="font-family: 宋体; font-size: 11pt; font-weight: bold; padding-left: 40pt; line-height: 160%">个反斜杠</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 240%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">要使一个</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">$</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 240%">字符能够在模式中匹配，必须使用</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">&quot;</span><a href="$" style="font-family: Times New Roman; font-size: 11pt; font-weight: bold; text-decoration: underline; color: #0000ff">\\\</a><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">$</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 240%">&quot;</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.9 </span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">特殊字符一览</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">方括号外的特殊字符（</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">p92</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">）</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">方括号内的特殊字符（</span><span style="font-family: Consolas; font-size: 12pt; line-height: 240%">p92-93</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">）</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">4.6.10 </span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; color: #000000; line-height: 160%">在智能表单中应用</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">当在一个</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 240%">字符类</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">的</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 240%">开始</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">或</span><span style="font-family: 宋体; font-size: 12pt; font-weight: bold; line-height: 240%">末尾</span><span style="font-family: 宋体; font-size: 12pt; line-height: 240%">使用点号时，点号将失去其特殊字符的意义，只能成为一个点号字符。</span></div>
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<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.7 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">用正则表达式查找子字符串</span><span style="font-family: Calibri; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">(p93)</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">POSIX</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">风格：</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">ereg()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">和</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">eregi()</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">int </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">ereg</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">(string </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ed7d31; line-height: 170%">pattern</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">, string </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ed7d31; line-height: 170%">search</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">, array [</span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ed7d31; line-height: 170%">matches</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">搜索字符串</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">search</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">，如果找到了与</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">pattern</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">匹配的字符串，则存储在</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">matches</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">中</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">eregi()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，不区分大小写，其余同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">ereg</span></div>
<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.8 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">用正则表达式替换子字符串</span><span style="font-family: Calibri; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">(p94)</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; color: #ff0000; line-height: 170%">ereg_replace()</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">, eregi_replace()</span></div>
<div><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">string</span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #ff0000; padding-left: 21pt"> ereg_replace</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">(string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #c45911; padding-left: 21pt">pattern</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">, string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #c45911; padding-left: 21pt">replacement</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">, string </span><span style="font-family: Consolas; font-size: 11pt; font-weight: bold; font-style: italic; color: #c45911; padding-left: 21pt">search</span><span style="font-family: Consolas; font-size: 11pt; font-style: italic; color: #2f5496; padding-left: 21pt">)</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">在</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">search</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">中查找正则表达式</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">pattern</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">的字符串，用</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">replacement</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">来替换</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">eregi_replace()</span><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">，不区分大小写，其余同</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">ereg_replace()</span></div>
<div><span style="font-family: 微软雅黑; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">4.9 &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">使用正则表达式分割字符串</span><span style="font-family: Calibri; font-size: 16pt; font-weight: bold; padding-left: 70pt; line-height: 170%">(p94)</span></div>
<div><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">array </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ff0000; line-height: 170%">split</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">(string </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ed7d31; line-height: 170%">pattern</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">, string </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ed7d31; line-height: 170%">search</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%"> [, int </span><span style="font-family: Consolas; font-size: 12pt; font-weight: bold; color: #ed7d31; line-height: 170%">max</span><span style="font-family: Consolas; font-size: 12pt; line-height: 170%">]);</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">将</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">search</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">分割为符合正则表达式模式</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">pattern</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">的子串，将子字符串返回到数组中</span></div>
<div><span style="font-family: 宋体; font-size: 10pt; font-weight: bold; padding-left: 40pt; line-height: 160%">* &nbsp; &nbsp; &nbsp; &nbsp;</span><span style="font-family: Consolas; font-size: 11pt; padding-left: 40pt; line-height: 160%">max</span><span style="font-family: 宋体; font-size: 11pt; padding-left: 40pt; line-height: 160%">指定进入数组中的元素个数</span></div>
<div><span style="font-family: 宋体; font-size: 12pt; line-height: 170%">同样的功能，正则表达式函数运行效率低于字符串函数</span></div>
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